There have been various signs in the past available to record time and other information with regard to store openings and closings. There is the conventional clock with a pair of manually movable hands to designate when the store will be opened or closed. The same type of construction has been used by salesmen to indicate when they will return to their offices.
In addition, there are certain forms of indicia registering devices wherein there is a fixed back member and a rotatable front member having a window therein which can be moved to expose information printed on the fixed member.
With regard to calendars, there have been those type of perpetual calendar where magnets are used to draw the desired dates into proper alignment for registering, as well as a perpetual calender wherein the differing color for registry behind the indicia is movable, such as is contained in my copending U.S. patent application, Ser. No. 660,340, filed Feb. 23, 1976.